[Locoblonde08]

So I have this problem.

What will be the new volume if 155 mL of He gas at 100°C and 0.953 atm is cooled to 21°C and the pressure is increased to 1.05 atm?

I decided to use P1V1/T2=P2V2/T1 but it didn't work.

Could someone please help? Thanks!

[Arkcon]

Really?  Plug in the numbers and let's see what you get.

[Locoblonde08]

I got 178 but the webassign marked it wrong.

[sjb]

P₁V₁ = nRT₁, is equivalent to P₁V₁/T₁ = nR

P₂V₂ = nRT₂, is equivalent to P₂V₂/T₂ = nR

As the sample of gas is the same in both cases, nR is the same, so

P₁V₁/T₁ = P₂V₂/T₂, or

P₁V₁T₂ = P₂V₂T₁, or

P₁V₁T₂ / P₂T₁ = V₂

Plug in and away you go. Could it be that you made an arithmetic error?

Does webassign need units, or check your significant figures (though 178 is right in the latter regard)?

S

PS further, as you've increased the pressure and decreased the temperature, does an increase in volume sound right?

[billnotgatez]

when you computed did you use K temp instead of C
I did not get near 178